Method and device for open-loop speed control of an electric toy car

ABSTRACT

The invention relates to a method and a device for open-loop control of the speed of an electrically driven toy car on a lane-guided racetrack. By means of a hand-actuatable closed-loop control device, the speed of the toy car can be adjusted to at least two speed levels. To adjust the magnitude of the first speed level as a fraction of the second speed level, the closed-loop control device is preferably programmable so that via the open-loop control device, the speed of the toy car is adjusted between a zero position and the first speed level and, after actuation of a selection switch, the speed of the traveling toy is adjustable between the zero position and the second speed level. The invention permits the adjustment of partial speeds of a toy car on a racetrack without using a transformer.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to a method and device for open-loop speed control of an electrically driven toy car on a lane-guided racetrack.

[0003] 2. The Prior Art

[0004] The speed of toy cars on a racetrack is usually adjusted by a hand-held closed-loop controller, which is generally pistol-shaped, and which enables open-loop speed control of the toy car between a zero position and a maximum position. Because of excessive acceleration of the toy cars, especially by inexperienced players, the tracks, cars and surroundings of the tracks can be damaged, especially by cars flying out of the curves. The traditional means of preventing this was to provide a transformer, with which the basic speed of the car could be controlled by the open-loop technique. New regulations have been enacted for toy cars for children, however, and the use of such transformers is no longer permitted.

[0005] It is further known, especially in the case of remotely steered toy cars, that the running speed can be adjusted up to a certain value in a first closed-loop control range and, after actuation of a so-called boost key, a higher speed can be reached. The boost key can be designed as a separate key, but it can also be constructed so that after a first speed level has been reached, the open-loop speed control key must overcome an obstruction in order to reach the second speed range.

[0006] There are also known toy cars whose function is adjustable by operation of programming keys. For example, programmable running behavior of the traveling toy can be achieved by a string of different commands input via typing keys in a keyboard arrangement.

[0007] Finally, it is known that traveling toys can be controlled by the open-loop technique by driving their motors electrically via a pulse-width open-loop controller, in order to achieve closed-loop control of the running speed.

SUMMARY OF THE INVENTION

[0008] It is therefore an object of the invention to provide a method and device for open-loop speed control of an electric toy car on a lane-guided racetrack, to permit the adjustment of different speed levels without the use of a transformer, ensure high safety and permit great playing enjoyment.

[0009] The invention relates to a method for open-loop control of the speed of an electric toy car on a lane-guided racetrack via a hand-actuatable closed-loop control device. The speed of the toy car can be adjusted to at least two speed levels. The second speed level can then represent the maximum attainable speed, which is achievable based on the electronic system, the voltage supply, the mechanical construction and the condition of the track and car. In the range between zero position and the second speed level, the magnitude of the first speed level can be programmed by the closed-loop control device to be a fraction of the second speed level.

[0010] By means of an open-loop control device, the speed of the toy car can then be adjusted between a zero position and the first speed level, and by actuating a selection switch the speed of the toy car is adjustable between the zero position and the second speed level. Given appropriate definition of the speed levels, the open-loop control device can therefore adjust the speed of the traveling toy between the zero position and the first speed level during regular play. Only when a selection switch, which can be a boost key, for example, is pressed, is the speed range increased to between the zero position and the second speed level.

[0011] With the present invention, the selection switch or boost key must be additionally actuated to reach the second speed level. Thus in normal play, the risk of cars flying out of the track or of damage to the surroundings is decreased.

[0012] In a preferred embodiment of the invention, further speed levels can be programmed or selected between the zero position and the second speed level.

[0013] Adjustment of a speed level is achieved preferably by programming a microprocessor.

[0014] The second speed level can be reached by a single actuation of the selection switch, but in a preferred embodiment, the second speed level is reached gradually, and only as long as the selection switch is simultaneously actuated.

[0015] The magnitude of the speed levels is determined, for example, by programming, preferably by manual actuation of function stages of a momentary-contact switch on the closed-loop control device. The magnitude of the speed level is then stored by actuating a separate switching means. The function stage of a momentary-contact switch can be reached, for example, by pressing a boost key for longer than 5 seconds. By alternating actuation of plus and minus keys of the open-loop control device, it is possible, for example, to select a specified speed level. This value can then be stored in a memory of a microprocessor device by once again actuating the boost key for sufficient time.

[0016] The respective functions of actuation can be shown on a display device, wherein two LEDs can be provided for assistance.

[0017] In the device according to the invention, there is a closed-loop control device with a microprocessor for programmable definition of at least two speed levels of the toy car. There is also an open-loop control device for adjustment of the speed of the toy car from a zero position up to a selected speed level. By means of a selection switch, the speed level can be selected for the open-loop control device.

[0018] The toy car is driven by pulse-width modulation controllable by the open-loop technique, in which a selected stored speed level represents the maximum value of the speed of the toy car that can be achieved with the open-loop control device via adjustment of the pulse-width modulation.

[0019] The present invention allows safer play without use of a transformer and without restriction of function. The programming capability of the closed-loop control device also permits expanded adjustment capabilities for different speed levels. It is also possible to add running characteristic curves such as acceleration profiles or braking profiles to the selectable speed levels. The toy car therefore behaves in conformity with the selected input information during adjustment of a particular speed level.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawing. It is to be understood, however, that the drawing is designed as an illustration only and not as a definition of the limits of the invention.

[0021] The single FIGURE shows a schematic view of a closed-loop control device according to the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] As shown in the FIGURE, closed-loop control device 1 is installed in a rectangular case, similar to a television remote controller. The connection to the racetrack is established by a lead 4. It is also possible, however, to provide open-loop control in the form of infrared or radio signals, in order to permit wireless operation. The current supply is preferably drawn from commercial batteries or an accumulator.

[0023] Below display 3 there are two LEDs 8, 9, which display the operating status of the closed-loop control device. The LEDs can be designed as separate LEDs or they can also be configured as one combined single LED, which can change between two colors.

[0024] When one color is displayed, for example, it means that the closed-loop control device is in programming mode, whereas the appearance of another color indicates the selected speed level. The respective levels and profiles can preferably be shown on display 3.

[0025] Open-loop control of the traveling toy takes place by means of open-loop control device 2, which is part of closed-loop control device 1. There are two keys 5, 6, of which key 5 represents a minus key and key 6 is a plus key. The speed of the traveling toy can be increased by actuating the plus key, whereas the speed can be reduced by actuating the minus key. The function of the keys can be designated so that the speed can be increased or decreased by tapping the keys several times. Alternatively, the duration of actuation can also be used for open-loop control.

[0026] The maximum speed value achievable with the plus key (first speed level) is limited. The speed can be further increased only by actuating (additionally or continuously) boost key 7. Experienced players are therefore able to achieve a greater speed and thus to make play correspondingly more exciting.

[0027] The programming mode of the device is accessed, for example, by actuating boost key 7 for longer than 5 seconds. Correspondingly, the programming status can be indicated on one of the LEDs 8 or 9 as well as additionally on display 3.

[0028] When the device is switched to programming mode, it is possible by actuating plus and minus keys 5, 6 to adjust a particular speed level, which either appears as a coded number in display 3 or can be shown directly in clear text in a correspondingly more sophisticated display 3.

[0029] The selected speed levels can be stored by pressing boost key 7 once again for a sufficiently long time. Other actuating command strings are also conceivable.

[0030] Instead of two separate plus and minus keys 5, 6, there can also be an operating rocker. Furthermore, the closed-loop control device can also be constructed in the form of a standard pistol-type open-loop controller. The respective position of the trigger lever corresponding to a particular adjustment of the ratio of plus and minus keys 5, 6 in the device is illustrated in the FIGURE.

[0031] The inventive device can be reprogrammed at any time, in which particular speed levels can be preset as standard values at the factory. There can also be included speed profiles, such as starting and braking maneuvers. The adjusted speed values are transmitted to the toy car via pulse-width modulation. Analog open-loop controllers are also possible.

[0032] When the drive is turned off in zero position, the drive motor is preferably short-circuited, in order to achieve direct braking.

[0033] Accordingly, while only a single embodiment of the present invention has been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention. 

What is claimed is:
 1. A method for open-loop control of the speed of an electrically driven toy car on a lane-guided racetrack, comprising: programming a hand-actuatable closed loop control device to adjust the magnitude of a first speed level as a fraction of a second speed level, programming an open loop control device to adjust the speed of the toy car between a zero position and the first speed level; and providing a selection switch such that the speed of the toy is adjustable between the zero position and the second speed level after actuation of the selection switch.
 2. The method according to claim 1 , wherein further speed levels are adjustable by further selection switches.
 3. The method according to claim 1 , wherein the adjustment of a speed level is achieved by programming a microprocessor.
 4. A method according to claim 1 , wherein the second speed level is reached only as long as the selection switch is simultaneously actuated.
 5. A method according to claim 1 , wherein the magnitude of the speed levels is determined by manual actuation of function stages of a momentary-contact switch on the open-loop control device, the magnitude of the speed levels being stored by actuation of a separate switching means.
 6. A device for open-loop control of the speed of an electric toy car, comprising: a closed-loop control device with a microprocessor for programming at least two speed levels of the toy car; an open-loop control device that adjusts the speed of the toy car beginning from a zero position up to a selected speed level, and a selection switch for selecting the speed level for the open-loop control device.
 7. A device according to claim 6 , further comprising an input key on the closed loop control device for input of a selected magnitude of a speed level, wherein the selected magnitude of the speed level is stored by a separate switching means in a memory of the microprocessor.
 8. A device according to claim 7 , wherein the toy car is controlled by the open-loop technique by pulse-width modulation, wherein a selected stored speed level represents a maximum achievable speed of the toy car with the open-loop control device via adjustment of the pulse-width modulation. 